Water- based fire protection systems such as discussed in NFPA 13, NFPA 15 and other NFPA Installation Standards are well known as are systems with other type of extinguishing agents such as halocarbon clean agents, inert gas clean agents and water-mist systems. In recent years, various manufacturers have developed a hybrid system of both water mist and inert gas agents that has proven effective in certain applications. As these hybrid systems did not quite fall under the requirements of existing standards such as NFPA Standard on Water Mist Fire Protection Systems, and NFPA 2001, Standard on Clean Agent Fire Extinguishing Systems, a new standard was developed, NFPA 770: Standard on Hybrid (Water and Inert Gas) Fire-Extinguishing Systems.